Antitumor Activity of Ethanolic Extract from Thymbra Spicata L. aerial Parts: Effects on Cell Viability and Proliferation, Apoptosis Induction, STAT3, and NF-kB Signaling

Abstract

Thyme-like plants including Thymbra spicata L. are widely used as food and folk medicinal remedies in the Mediterranean area. This study aimed to explore the in vitro antitumor potential of polyphenol-enriched extracts from aerial parts of T. spicata. The ethanolic extract significantly inhibited proliferation of different human tumor cell lines, without significant effects on non-neoplastic cells. A deeper investigation of the molecular mechanism sustaining the in vitro antitumor activity of the extract was carried on the human breast cancer cells MCF-7 in comparison with the normal breast cells MCF-10A. The effects on MCF-7 cells were associated with the following: (i) production of reactive oxygen species (ROS) and release of nitric oxide; (ii) apoptosis induction; and (iii) reduction in STAT3 and NF-kB phosphorylation. The ethanolic extract from T. spicata leaves might represent a novel therapeutic tool in combination with conventional chemotherapy to reduce the adverse side effects and drug resistance.

Acknowledgements

Our thanks go to Dr. Fatima Saad and Dr. Rita Fabbri for their technical support in the laboratory, and Prof. Sara Ferrando for the microscopy facility.

Disclosure Statement

No potential conflict of interest was reported by the authors.

Author’s Contribution

All authors contributed to this work significantly: AD and LV conceived the focus of the paper, designed the experimental activity, and wrote the manuscript; MK performed cultures and treatment of cells, carried on the experimental, analyzed the date, and participated in writing the manuscript; NS performed spectrophotometric analyses; HK participated in conceiving and designing the study, contributed to data analysis, and critically revised the manuscript; FB performed optical microscopy experiments; AP performed flow cytometer analyses and elaborated data; AV participated in cell cultures and treatments. All the authors contributed to discussion and interpretation of the results.

All authors have read, approved, and agreed to submit the manuscript to Nutrition and Cancer and no part of the work has been published before.

Additional information

Funding

This research was supported by grants from Lebanese University (4/6693) and University of Genova (FRA 2017 and 2018).